Manufacturing method of graphene metal composite material

ABSTRACT

A manufacturing method of a graphene metal composite material includes the steps of providing metal powder including metal particles, graphene powder including graphene pieces and binder including wax material, wherein each graphene piece includes graphene molecules connected with each other and including six carbon atoms annually connected, and one of the carbon atom of each graphene molecule is bonded with a functional group by an SP3 bond; mixing the powders and the binder into a powder material, wherein the SP3 bond is heated and broken by friction, and the graphene molecules are connected with each other via the broken SP3 bond to wrap the respective metal particles; melting and molding the powder material to form a green part; removing the binder from the green part to form a brown part; and sintering the brown part to form a metal main part embedded a three-dimensional mash formed by the graphene molecules.

TECHNICAL FIELD

The present disclosure is related to a graphene metal composite material, and in particular to a manufacturing method of a graphene metal composite material with graphene uniformly spread therein.

BACKGROUND

Currently, manufacturing and application of silicon carbide and aluminum oxide used for reinforcing copper matrix composite have been almost fully developed, however overall performances of the materials are not sufficient for the increasing demand thereof. Graphene is a suitable reinforcement with excellent mechanical, thermal and electrical properties. However, researches of reinforcing copper or matrix composite and aluminum matrix composites by graphene are still new and further relevant researches are required. The main problem of the research is how to spread graphene into a copper aluminum body and meanwhile form a well contact between the graphene and the metal without damage of the graphene.

In views of this, in order to solve the above disadvantage, the present inventor studied related technology and provided a reasonable and effective solution in the present disclosure.

SUMMARY

A manufacturing method of a graphene metal composite material with graphene uniformly spread therein is provided in the present disclosure.

A manufacturing method of a graphene metal composite material provided in the present disclosure has the following steps: providing metal powder, graphene powder and a binder, the metal powder comprising a plurality of metal particles, the binder comprising a wax material, the graphene powder comprising a plurality of graphene pieces, each graphene piece comprising a plurality of graphene molecules connected with each other, each graphene molecule comprising six carbon atoms 200 b annually connected with each other, one of the carbon atoms of each graphene molecule is connected with a functional group by an SP3 bond; mixing the metal powder, the graphene powder and the binder into a powder material, and the SP3 bond bonding each functional group is heated to broken by friction and the functional groups are thereby separated from the respective graphene molecules, each graphene molecule is bonded with another graphene molecule by the broken SP3 bond, and the respective metal particles are thereby wrapped by the graphene molecules; heating the powder material to melt into a liquid mixture material mixed of the metal powder, the binder in liquid phase and the graphene powder; injection the liquid mixture material into a mold for molding and solidifying to form a green part; removing the binder from the green part to transform the green part into a brown part, firstly solvent debinding the green part to remove a part of the binder and the green part is thereby transformed into the brown part with pores therein, and sequentially thermal debinding between 140□ and 170□; sintering the brown part to melt the metal particles into a metal main part and the graphene molecules thereby form a three-dimensional mash embedded in the metal main part.

According to the manufacturing method of the graphene metal composite material of the present disclosure, the metal particles and the graphene pieces are uniformly spread in the green part, and the respective graphene pieces are wrapped by the binder in solid phase and thereby adhered with the metal particles.

According to the manufacturing method of the graphene metal composite material of the present disclosure, the green part is immersed into a solution to dissolve the binder when solvent debinded.

According to the manufacturing method of the graphene metal composite material of the present disclosure, the binder is vaporized by heating the brown part when the brown part is thermal debinded.

According to the manufacturing method of the graphene metal composite material of the present disclosure, the metal main part could be made of aluminum or copper.

According to the manufacturing method of the graphene metal composite material of the present disclosure, the functional group could be an oxygen-containing functional group. the functional group could be seearate.

According to the manufacturing method of the graphene metal composite material of the present disclosure, a coupling agent is 0.5 to 2 weight percentage of the binder, and the coupling agent could be titanate or organochromium compound.

According to the manufacturing method of the graphene metal composite material of the present disclosure, a dispersant is 5 to 20 weight percentage of the binder, the dispersant is sec-hexyl alcohol, polyacrylamide or fatty acid polyethylene glycol ester.

In conclusion, according to the manufacturing method of the graphene metal composite material of the present disclosure, graphene powder is mixed with metal powder and binder, a mixture of metal particle, graphene piece and binder could be made by the mixing and granulation process, and after molding and debinding processes are undergone. After a sintering process, the respective sphere formed by the graphene molecules covering the respective metal particles form a three-dimensional mash embedded in the metal main part in the end product, and a heat transfer coefficient of the end product is thereby increased.

BRIEF DESCRIPTION OF DRAWING

The present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying draw.

FIG. 1 is a flowchart showing a manufacturing method of a graphene metal composite material according to an embodiment of the present disclosure.

FIG. 2 is a schematic view showing a powder material according to the manufacturing method of the graphene metal composite material recited in the embodiment of the present disclosure.

FIG. 3 is a schematic view showing a molding step according to the manufacturing method of the graphene metal composite material recited in the embodiment of the present disclosure.

FIG. 4 is a schematic view showing a green part according to the manufacturing method of the graphene metal composite material recited in the embodiment of the present disclosure.

FIG. 5 is a schematic view showing a brown part according to the manufacturing method of the graphene metal composite material recited in the embodiment of the present disclosure.

FIG. 6 is a schematic view showing a graphene metal composite material according to the embodiment of the present disclosure.

FIG. 7 is a schematic view showing graphene.

FIG. 8 is a schematic view showing functional graphene.

DETAILED DESCRIPTION

According to FIGS. 1 to 6, a graphene metal composite material is provided in an embodiment of the present disclosure. According to the present embodiment, the manufacturing method of the graphene metal composite material has at least following steps.

According to step a, metal powder, graphene powder and binder 300 are provided, the metal powder could be aluminum powder or copper powder. The metal powder includes a plurality of metal particles 100 (aluminum particles or copper particles), the graphene powder includes a plurality of graphene pieces 200, and each graphene piece 200 includes a plurality of graphene molecules 200 a connected with each other shown in FIG. 7. According to FIGS. 1, 7 and 8, the graphene piece shown in FIG. 7 could be modified by connected with a functional group and thereby transformed into a functional graphene shown in FIG. 8. According to the present embodiment, the functional group is preferably oxygen-containing functional group, such as seearate, the oxygen-containing functional group is bonded with one of carbon atoms 200 b of the graphene by an SP3 bond. Each graphene molecule 200 a includes six carbon atoms 200 b annually connected with each other. According to FIG. 8, one of the carbon atoms 200 b of each graphene molecule 200 a is bonded with a functional group by an SP3 bond. The main ingredients of the binder 300 are wax materials such as paraffin, microcrystal wax and acrylic wax, and generally includes low molecular weight thermoplastic polymer or oil. A coupling agent for fixing the wax material such as titanate and organochromium compound is 0.5 to 2 weight percentage of the binder 300. A dispersant for uniformly disperse the wax material is 5 to 20 weight percentage of the binder 300, and the dispersant could be sec-hexyl alcohol, polyacrylamide or fatty acid polyethylene glycol ester.

According to step b, the metal powder, the graphene powder and the binder 300 provided in step a are processed by a mixing and granulation process and thereby transformed into a powder material 10. The metal powder, the graphene powder and the binder 300 are uniformly mixed in the mixing and granulation process, and the metal particles 100 and the graphene pieces 200 of the powder material 10 could be dispersed in the dispersant and thereby wrapped by the binder 300. According to step b, a dispersibility of the graphene piece 200 in the metal powder and the binder 300 could be increased by functionalizing the graphene powder. The respective graphene pieces 200 have like charges when a certain number of functional groups added in to the graphene piece 200 repel. When the respective graphene pieces 200 are bonded with functional groups, the like charges repel each other, the graphene pieces 200 repel each other and thereby uniformly spread in the dispersant and the binder 300. In the mixing process according to step b, the frictions between the functional graphene pieces 200 generate heat and the SP3 bond of the oxygen-containing functional group could be broken by absorbing the heat, and the oxygen-containing functional groups are thereby released. Accordingly, the carbon atom 200 b originally bonded with the oxygen-containing functional group could be immediately rebounded with another broken SP3 bond of another carbon atom 200 b in another graphene piece 200, and the graphene piece 200 thereby could be connected into multiple sphere layers to wrap the respective metal particles 100, and the sphere layers are preferably less than 10 layers.

According to step c following step b, heating to melt the powder material 10 into a liquid mixture material 20. The liquid mixture material 20 includes metal powder, liquid binder 300 and graphene powder.

According to step d following step c, the liquid mixture material 20 is injected into mold 400 for molding, and solidified and transformed into a green part 30. The green part 30 includes metal particles 100 and graphene pieces 200 uniformly spread therein, and the respective graphene pieces 200 are wrapped by the solidified binder 300 and thereby adhered with the metal particle 100.

According to step e following step d, the binder 300 is removed from the green part 30 by debinding the green part 30, and the green part 30 is thereby transformed into a brown part 40. The debinding process could be a thermal debinding process or a solvent debinding (or watery debinding) process. Thermal debinding process is a heat treatment process to the green part 30, inert gas is used as a flow medium and heated for pyrolysis and the binder 300 is vaporized and exhausted by the flow medium. The binder 300 could be vaporized in high temperature and vacuum of vacuum debinding process, and exhausted after distillation. The binder 300 is dissolved by solvent in the watery/solvent debinding process. Specifically, thermal debinding could be processed with watery/solvent debinding, the green part 30 is watery/solvent debinded firstly to dissolve a part of the binder 300, and pores are therefore formed in the brown part 40. The green part 30 is sequentially thermal debinded, the pores allow the high temperature gas to flow therethrough, and the rest part of binder 300 could be thereby decomposed and exhausted. According to step e, the thermal debinding step is processed under a temperature lower than a melting point of the metal particle 100 and higher than a melting point or a boiling point of the binder 300, the surrounding is heat up to 140□ to 170□. The graphene piece 200 is unmeltable and the boiling point thereof is much higher than the melting points or boiling points of the metal particle 100 and the binder 300, and the graphene piece 200 therefore could withstand the thermal treatment process.

According to step f following step e, the brown part 40 is sintered, the metal particles 100 are thereby melted into a metal main part 100 a, a surrounding for sintering metal particles 100 made of copper should be heat up to 1050□ for 1 hour, a surrounding for sintering metal particles 100 made of aluminum should be heat up to 600□ for 1 hour. The graphene piece 200 is unmeltable and the boiling point thereof is much higher than the melting points or boiling points of the metal particle 100 and the binder 300, and the graphene piece 200 therefore could withstand the thermal treatment process. Furthermore, the graphene pieces 200 could be uniformly spread in the metal main part 100 a. The metal main part 100 a could be made of aluminum or copper. Thereby, an end product 50 of the graphene metal composite material according to the present disclosure is manufactured.

According to FIG. 6, a graphene metal composite material end product 50 could be manufactured by the aforementioned manufacturing method of graphene metal composite material according to the present disclosure. The graphene metal composite material includes a metal main part 100 a and a plurality of graphene molecules 200 a embedded in the metal main part 100 a. Specifically, the metal main part 100 a could be made of aluminum or copper, and the graphene molecules 200 a is uniformly spread in the metal main part 100 a.

In conclusion, according to the manufacturing method of the graphene metal composite material of the present disclosure, graphene powder is mixed with metal powder and binder 300, a mixture of metal particle 100, graphene piece 200 and binder 300 could be made by the mixing and granulation process, and after molding and debinding processes are undergone. After a sintering process, the respective sphere formed by the graphene molecules 200 a covering the respective metal particles 100 form a three-dimensional mash embedded in the metal main part 100 a in the end product 50, and a heat transfer coefficient of the end product 50 is thereby increased. The heat transfer coefficient of the metal part the is increased by the graphene, and a heat conductor made of the graphene metal composite material for transferring a specific amount of heat could be smaller than a pure metal heat conductor. Moreover, the graphene piece 200 could be arranged more regularly by adding the functional groups, and heat could be spread more uniformly thereby than a conventional redden spread structure. Therefore, the present disclosure has an excellent heat transfer performance.

Although the present disclosure has been described with reference to the foregoing preferred embodiment, it will be understood that the disclosure is not limited to the details thereof. Various equivalent variations and modifications can still occur to those skilled in this art in view of the teachings of the present disclosure. Thus, all such variations and equivalent modifications are also embraced within the scope of the present disclosure as defined in the appended claims. 

What is claimed is:
 1. A manufacturing method of a graphene metal composite material, comprising the following steps: a) providing metal powder, graphene powder and a binder, the metal powder comprising a plurality of metal particles, the binder comprising a wax material, the graphene powder comprising a plurality of graphene pieces, each graphene piece comprising a plurality of graphene molecules connected with each other, each graphene molecule comprising six carbon atoms annually connected with each other, one of the carbon atoms of each graphene molecule is connected with a functional group by an SP3 bond; b) mixing the metal powder, the graphene powder and the binder into a powder material, and the SP3 bond bonding each functional group being heated to broken by friction and functional groups thereby being separated from respective graphene molecules, each graphene molecule being bonded with another graphene molecule by the broken SP3 bond, and respective metal particles being thereby wrapped by the graphene molecules; c) heating the powder material to melt into a liquid mixture material mixed of the metal powder, the binder in liquid phase and the graphene powder; d) injection the liquid mixture material into a mold for molding and solidifying to form a green part; e) removing the binder from the green part to transform the green part into a brown part, firstly solvent debinding the green part to remove a part of the binder and the green part being thereby transformed into the brown part with pores therein, and sequentially thermal debinding between 140□ and 170□; and f) sintering the brown part to melt the metal particles into a metal main part and the graphene molecules being thereby formed a three-dimensional mash embedded in the metal main part.
 2. The manufacturing method of the graphene metal composite material according to claim 1, wherein the metal particles and the graphene pieces are uniformly spread in the green part in step d, and the respective graphene pieces are wrapped by the binder in solid phase and thereby adhered with the metal particles.
 3. The manufacturing method of the graphene metal composite material according to claim 1, wherein the green part is immersed into a solution to dissolve the binder when solvent debinded in step e.
 4. The manufacturing method of the graphene metal composite material according to claim 1, wherein the binder is vaporized by heating the brown part when the brown part is thermal debinded in step e.
 5. The manufacturing method of the graphene metal composite material according to claim 4, wherein the metal main part is made of aluminum or copper.
 6. The manufacturing method of the graphene metal composite material according to claim 1, wherein the functional group is an oxygen-containing functional group.
 7. The manufacturing method of the graphene metal composite material according to claim 6, wherein the functional group is seearate.
 8. The manufacturing method of the graphene metal composite material according to claim 1, wherein a coupling agent is 0.5 to 2 weight percentage of the binder, and the coupling agent is titanate or organochromium compound.
 9. The manufacturing method of the graphene metal composite material according to claim 1, wherein a dispersant is 5 to 20 weight percentage of the binder, and the dispersant is sec-hexyl alcohol, polyacrylamide or fatty acid polyethylene glycol ester. 